一、操作要求准确化 教材中许许多多图例,并非统一的操作模式。它需要教师仔细揣摩,把握住各自的要求。如“20以内的进位加法”,从单元的整体看——教材中安排了15道例题,从具体到抽象层层递进:先让学生操作建立“凑十”的表象(6道例题);再逐步脱离直观,在算式中标“凑十”的过程(4道例题);最后看算式写得数(5道例题)。从一节的局部看——“9加 First, the operation requirements Accurate textbooks in many illustrations, not a unified mode of operation. It requires teachers to carefully figure out, to seize their own requirements. For example, “Carry Addition from Within 20”, from the perspective of the unit as a whole - 15 examples are arranged in the textbook, proceeding from the concrete to the abstract level: letting the students manipulate the appearance of “Minato Ten” (six cases); Then gradually out of the visual, in the formula won the “Minato ten” process (4 cases); Finally see the number of mathematical expressions (5 cases). From a section of the local look - "9 plus